The major greenhouse gas in the Earth is CO2; currently, the increase of CO2 emission results in global warming and climate change; the major reason of the increase of CO2 emission is the exhaust gas of gasoline vehicles. For the purpose of solving the above problems, the development of electric vehicles of low noise, low pollution and energy-saving has become the trend in the future.
However, as an electric vehicle needs to be powered by batteries, so the electric vehicle needs a battery management system (BMS) to prevent the batteries from malfunctioning in order to make sure that the driver can safely drive electric vehicle.
In general, the safe protection items provided by currently available battery management system includes over-voltage charge protection function, over-current charge protection function, over-temperature discharge protection function, over-temperature charge protection function and charge time protection function, etc. When a battery management system activates over-voltage charge protection function, the battery management system activates a protection function (e.g. turning off the charge switch of the batteries) when the voltage of the batteries in the charge status exceeds a voltage threshold value, and then deactivates the protection function when the voltage of the batteries in the charge status is lower than the voltage threshold value.
When executing over-current charge protection function, the battery management system activates a protection function (e.g. turning off the charge switch of the batteries) when the current of the batteries in the charge status exceeds a current threshold value, and then deactivates the protection function when the current of the batteries in the charge status is lower than the current threshold value.
When executing over-temperature charge protection function, the battery management system activates a protection function (e.g. turning off the charge switch of the batteries) when the temperature of the batteries in the charge status exceeds a temperature threshold value, and then deactivates the protection function when the temperature of the batteries in the charge status is lower than the temperature threshold value.
When executing over-temperature discharge protection function, the battery management system activates a protection function (e.g. turning off the discharge switch of the batteries) when the temperature of the batteries in the discharge status exceeds a temperature threshold value, and then deactivates the protection function when the temperature of the batteries in the discharge status is lower than the temperature threshold value.
When executing charge time protection function, the battery management system turns off the charge switch of the batteries when any one of the series voltages of the batteries reaches a default value or the charger detects that the charge time exceeds a default charge time.